The invention relates to a modular block for osmotic methods of separation in which a pressure permeation unit consists of a pressure tube sealed at its end with a filtration unit and the solution is supplied and discharged and the permeate discharged via flanges provided on the covers of the pressure tube. With this apparatus, it is possible to exchange and optionally recycle the filtration unit with very little manipulation.
Now that pressure permeation, i.e. ultra filtration and reverse osmosis are becoming increasingly important, problems of economy are also brought markedly into the foreground. In addition to the expense incurred for power and personnel, the expenses for apparatus are of great importance for carrying out pressure permeation economically. Most flat membrane modules are so complicated in design that they cannot be "throw away modules" but are invariably designed for exchange of membranes. Exchange of membranes of this type, however, is very labour-intensive and therefore associated with high costs. Moreover, the loss of production occurring during the membrane exchange time has to be added to the membrane exchange costs.
A pressure permeation apparatus is generally much simpler for the operator if he can replace the used modules by new modules without high labour costs. However, a mode of operation of this type presupposes that the production of the module is so inexpensive that when it is necessary to exchange the membrane, this can be omitted and the entire module, or rather the filtration unit, can be exchanged for a new one.
Such a module exchange is carried out, for example, in the case of winding modules, hollow fine modules and hollow fibre modules, in which process, however, the entire module, i.e. filtration unit has to be exchanged in addition to the pressure container.
It is not possible to solve all the problems of separation using this type of module. Thus, with the three above-mentioned types, it is only possible to process solid-containing liquid systems to a limited extent. In addition, the operating pressure is restricted to such low pressures in the case of hollow fibre capillaries that reverse osmosis cannot be carried out.
It is advantageous to traverse certain problems of material separation on strong flat membrane modules of the type known, for example, as plate frame modules of various designs.
Known flat membrane modules are, however, very expensive to design or produce. Encapsulations (German Offenlegungsschrift No. 25 42 957, German Auslegeschrift No. 16 42 808) or five-layered modular elements with a permeate absorbing shell (German Offenlegungsschrift No. 24 33 456) or brittle porous support plates of complicated geometry (German Offenlegungsschrift No. 26 03 505), interrupted substrates which can be coated uniformly only with difficulty (German Offenlegungsschrift No. 25 25 972) or elements which can only be connected in tandem and with which sealing problems arise (German Offenelgungsschrift No. 25 56 210) are known.
Modules of this type are usually not designed as single use modules but for exchange of the membrane or element. In order to change the course of flow, for example, during the transition from parallel to series connection, it is often necessary to use additional, separate sealing elements (German Offenlegungsschrift No. 25 42 957, Swiss Pat. No. 542 639) and to fit sealing elements or partition walls.